Triple coupler for flexible scaffold system

Information

  • Patent Grant
  • 6786302
  • Patent Number
    6,786,302
  • Date Filed
    Wednesday, February 20, 2002
    23 years ago
  • Date Issued
    Tuesday, September 7, 2004
    20 years ago
Abstract
A coupling apparatus is comprised of three couplers for interconnecting three scaffolding members. The locking devices for the couplers may be of a bolt-and-nut configuration or, advantageously, of a wedge and arm, tapered circular wedge and arm or over-centre hand-lever.
Description




FIELD OF THE INVENTION




This invention relates to couplers and more particularly to couplers for interconnecting scaffolding.




BACKGROUND OF THE INVENTION




Scaffolding is commonly constructed from lengths of steel or aluminum tubes interconnected to each other to form an open structural framework. The size and configuration of the structure depends on the application. The interconnection of the tubes is normally made by two right angle couplers (“double couplers”) which are joined together. One of these double couplers can interconnect two of the three tubes that will normally meet at a right angle crossing of a scaffold structure. A second double coupler is required to interconnect a third tube to the first two.




The couplers are normally locked to the tubes by one or more nut and bolt locking devices. However, such couplers suffer from disadvantages. Their fastening and unfastening is time consuming and is inconvenient in requiring use of a wrench. Additionally, two hands are normally required to hold the coupler during the initial stages of fastening and the nuts and bolts are often corroded, making it difficult to thread and tighten the nuts. Also, the locking device may be under or over tightened on the tubes, leading to slipping or thread stripping respectively, which may compromise the safety of the scaffold structure.




SUMMARY OF THE INVENTION




The invention may be summarised according to a first broad aspect as a coupling apparatus for interconnecting three scaffold members comprising: a support coupler and two connector couplers for attachment to three scaffold members; the support coupler having a base interconnected to the connector couplers, a lever hinged to the base, and a locking device, the base and the lever defining a pocket for laterally receiving a length of a scaffold member; the connector couplers each defining a pocket for receiving a length of a scaffold member and having a locking device; each of the locking devices being movable from a release condition, to allow a scaffold member to be positioned in or removed from the pocket, to a locked position, to secure the scaffold member in the coupler; wherein the pockets are oriented to secure three scaffold members at relative angles to each other.




The invention may be summarised according to a second broad aspect as a two coupler apparatus for interconnecting two scaffolding members wherein at least one coupler is defined by: a base interconnected to a second coupler; a lever hinged to the base, the base and the lever defining a pocket for laterally receiving a length of a scaffold member; an arm hinged to the base; the lever having an slot sized to receive the arm; the arm defining a hole positioned to extend beyond the lever when the arm is within the slot; a wedge adapted for insertion through the hole to slidably move against the lever when the arm extends within the slot to wedge the arm within the lever whereby the scaffold member is locked within the at least one coupler.




The invention may be summarised according to another broad aspect as a two coupler apparatus for interconnecting two scaffolding members wherein at least one coupler is defined by: a base interconnected to a second coupler; a lever hinged to the base, the base and the lever defining a pocket for laterally receiving a length of a scaffold member; an arm hinged to the base, the arm having a protrusion at a free end; the lever having an slot adapted to receive the arm; a circular wedge pivotally mounted on the arm, the circular wedge circumferentially increasing in thickness to define a cam surface for engagement with the protrusion; the circular wedge being rotatable on the arm between the lever and the protrusion in a direction of increasing thickness to create a wedging action between the protrusion and the cam surface acting to press the lever onto the scaffold member to lock the scaffold member within the pocket.




The invention may be summarised according to a further broad aspect as a two coupler apparatus for interconnecting two scaffolding members wherein at least one coupler is defined by: a base interconnected to a second coupler; a lever hinged to the base, the base and the lever defining a pocket for laterally receiving a length of a scaffold member; an over-centre hand-lever mechanism for intercoupling the base and the lever, the over-centre hand-lever mechanism having an adjustable length and being selectively actuatable when intercoupling the base and the lever to lock the lever and the base to a scaffold member.




Advantageously, the triple coupler allows three scaffold members to be interconnected with only one coupling apparatus thereby replacing the two double couplers normally used. Assembly is then achieved by the handling of one apparatus instead of two.




Additionally, the angle between the three scaffold members can be fixed by the triple coupler. This eliminates the need to adjust the angle of a second double coupler relative to a first double coupler as is necessary where two double couplers are used.




Specific embodiments of the couplers, namely the wedge coupler, the circular wedge coupler and the hand-lever coupler, have the advantage that they do not rely on threaded bolts and nuts to fasten the couplers around the scaffold members. This eliminates the problems of stripped or rusted threads associated with bolt-and-nut locking devices.




Additionally, the hand-lever coupler may be fastened or unfastened quickly without the use of any hand tools.




Also, the wedge coupler and the circular wedge coupler are simple to fabricate, may be fastened or unfastened rapidly and the circular wedge coupler has no separable parts.




Other aspects and features of the invention will become apparent to those of ordinary skill in the art upon review of the following description of specific embodiments of the invention in conjunction with the accompanying figures.











BRIEF DESCRIPTION OF THE DRAWINGS




Preferred embodiments of the invention will now be described with reference to the attached drawings in which:





FIG. 1

is a perspective view of a bolt-and-nut triple coupler in which segments of scaffolding tubes are shown.





FIG. 2

is a perspective view of the bolt-and-nut triple coupler of FIG.


1


.





FIG. 3

is a perspective view of a wedge triple coupler.





FIG. 4

is an enlarged perspective view of a wedge and an arm used in the triple coupler of FIG.


3


.





FIG. 5

is a perspective view of a circular wedge triple coupler.




FIG.


6


A and

FIG. 6B

are perspective views of a circular wedge and arm, shown separately and assembled, respectively, of the triple coupler of FIG.


5


.





FIG. 7

is a perspective view of a hand-lever triple coupler.





FIGS. 8A

,


8


B,


8


C and


8


D are perspective views of a base, an inner lever, a hand lever and a T-shaped catch assembly of the coupler of FIG.


7


.





FIG. 9

is a side view of a coupler of the hand-lever triple coupler of

FIG. 7

, with a scaffold member, in an open position.





FIG. 10

is the coupler of

FIG. 9

, shown to a larger scale, in an almost closed position.











DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT





FIG. 1

depicts a triple coupler


10


interconnecting a vertical scaffold member


8


A and two horizontal scaffold members


8


B,


8


C. The triple coupler


10


includes a heavy duty vertical support coupler


12


and two horizontal connector couplers


14


A,


14


B.





FIG. 2

depicts a base


16


of the vertical support coupler


12


. The base


16


has two plates


17


,


19


joined at a right angle. Two flanges


15


extend at right angles from the edges of the plates


17


,


19


. The flanges


15


have inner edges that define an arcuate pocket


22


. The flanges


15


have pair of registering holes that define a pivot axis


21


adjacent an outer end of the plate


19


and a pivot axis


28


adjacent an outer end of the plate


17


.




The base


16


further includes a lever


18


defined by a plate


25


that has two flanges


27


, and a horizontal slot


30


opening from the free end. The two flanges


27


extend from the free end of the plate


25


along its side edges and have inner edges that are arcuate. The lever


18


is pivotally connected, on the axis


21


, to the flanges


15


on the base


16


.




The coupler


12


includes a locking device


24


comprising a bolt


26


, which is pivotally connected to the base


16


on the axis


28


at the opposite side of the pocket


22


. A nut


34


is threaded on the bolt


26


which also carries a washer


32


. The horizontal slot


30


receives the bolt


26


when the bolt


26


is rotated about the pivot axis


28


and into position shown in FIG.


1


.




The vertical support coupler


12


is locked to the vertical scaffold member


8


A by the locking device


24


. The operation of the locking device


24


is as follows. The vertical scaffold member


8


A (

FIG. 1

) is placed into the pocket


22


. The lever


18


is then swung to close the flanges


27


around scaffold member


8


A. The lever


18


thus closes the pocket


22


. The flanges


27


and the flanges


15


grip the vertical scaffold member


8


A (

FIG. 1

) when the vertical support coupler


12


is closed. The bolt


26


is then swung into the slot


30


in the lever


18


and the nut


34


rotated against the washer


32


to press the lever


18


into gripping engagement with the scaffold member


8


A. Thus, when the nut


34


is tightened, the vertical scaffold member


8


A is securely locked in the pocket


22


of the coupler


12


.




The structure of each horizontal connector coupler


14


A,


14


B depicted in

FIGS. 1 and 2

is basically the same as that of the vertical support coupler


12


. Only the structure which differs will be described with reference to the lower horizontal connector coupler


14


B. Unless otherwise specified, the structure of the upper horizontal connector coupler


14


A is the same as that of the lower horizontal connector coupler


14


B.




The lower horizontal connector coupler


14


B has a stopper plate


48


near the pivot of a bolt


50


. The stopper plate


48


prevents the bolt


50


from rotating too far from its locked position when it is released. The stopper plate


48


maintains the bolt


50


at an angle in the range of 10° to 15° from the plane of a horizontal plate


43


of a base


42


.




The horizontal connector couplers


14


A,


14


B are rigidly fixed to the vertical support coupler


12


by rivets


36


. As shown in

FIGS. 1 and 2

, the horizontal connector couplers


14


A,


14


B are offset and orthogonal to each other and to the vertical support coupler


12


. The vertical plate


45


B of the base


42


of the lower horizontal connector coupler


14


B is riveted to the plate


17


of the vertical support coupler


16


and the vertical plate


45


A of the upper horizontal connector coupler


14


A is riveted to the plate


19


of the coupler


12


as is clearly shown in FIG.


2


. The vertical plate


45


B of the lower horizontal connector coupler


14


B extends below the plate


17


of the coupler


12


and the vertical plate


45


A of the upper horizontal connector coupler


14


A extends above the plate


19


of the coupler


12


. On a portion of the vertical plate


45


B, which extends below the coupler


12


, there is a reinforcing knot


40


. The reinforcing knot


40


is a roughly semi-hollow-ball shaped protrusion formed in the vertical plate


45


B. The reinforcing knot


40


prevents the bending of the vertical plate


45


B by pressing against the vertical scaffold member


8


A when a vertical force of the horizontal scaffold member


8


C against the base


42


would otherwise tend to bend the portion of the vertical plate


45


B extending below the base


16


. A vertical plate


45


A of the upper horizontal connector coupler


14


A does not have a similar reinforcing knot.




Other locking devices may be utilized as exemplified in the following Figures.

FIG. 3

depicts a triple coupler


60


which utilizes a bolt-and-nut locking device


62


to secure a vertical support coupler


64


as in

FIGS. 1

,


2


. However, two horizontal connector couplers


66


utilize a different locking device.




The couplers


66


have a base


72


with flanges having arcuate inner edges which define a pocket


76


. A lever


74


is hinged at one end to the base


72


. The lever


74


also has flanges with arcuate inner edges. The lever


74


has an outwardly open slot


78


as in the levers of the bolt-and-nut couplers of

FIGS. 1

,


2


. However, in the present embodiment, the bolt-and-nut have been replaced by an arm


70


and a wedge


68


.





FIG. 4

depicts the wedge


68


separately from the arm


70


. The arm


70


has a circular hole


71


adjacent one end and an elongate hole


80


adjacent the other end. The arm


70


is hinged to the base


72


by a pin (not shown) passing opposite the lever


74


through the hole


71


. The wedge


68


has a wide end


84


with a stopper


87


, and tapers to a narrow end


82


, which has a hole


86


defined therein.




In use, a scaffold member (not shown) is positioned into the pocket


76


and the lever


74


is rotated to close the pocket


76


around the scaffold member. The arm


70


is then rotated into the slot


78


such that a portion of hole


80


extends above the lever


74


. The small end


82


of the wedge


68


is slid through that portion of the hole


80


. As the wedge


68


(driven by hammer blows) is advanced through the hole


80


, the increasing taper of wedge


68


forces more of the arm above the lever


74


. The lever


74


is thus pressed against the scaffold member within the pocket


76


, thereby locking the scaffold member within the coupler


66


.




The wedge


68


is also designed to be retained within the hole


80


even when it is not locked against the lever


74


. In particular, the stopper


87


at the wide end


84


of the wedge


68


is sufficiently wide that it cannot fit through the hole


80


in the arm


70


. A retaining means (not shown) such as a cotter pin, rivet, or other fastener, is inserted through the hole


86


in order to retain the wedge


68


within the hole


80


.





FIG. 5

depicts a triple coupler


90


comprised of a bolt-and-nut coupler


92


and two circular wedge couplers


94


. The bolt-and-nut coupler


92


is essentially as described with respect to

FIGS. 1 and 2

but the two couplers


94


utilize another locking device. Each coupler


94


has a base


98


, with flanges having arcuate inner edges, which defines a pocket


100


. A lever


96


is hinged at one end to the base


98


. The lever


96


also has flanges with arcuate inner edges and can be swung to close the pocket


100


around a horizontal scaffold member (not shown). The lever


96


has an outwardly open slot


104


. This structure is the same as that of the bolt-and-couplers of

FIGS. 1

,


2


. However, in the present embodiment, the bolt-and-nut have been replaced with an arm


102


and a circular wedge


105


.





FIG. 6A

depicts the arm


102


and the circular wedge


105


separately. The arm


102


has a hole


101


adjacent one end for pivotal attachment to base


98


and at its opposite end a protrusion


112


projecting perpendicular to an axis of the hole


101


. The arm


102


is hinged to the base


98


, opposite the lever


96


, through the hole


101


. The circular wedge


105


has a hexagonal outer surface and a circular inner surface. The circular wedge


105


has a depression


108


, which defines the minimum thickness of the circular wedge


105


. A tapered upper surface


110


which begins at a leading edge


117


of the depression


108


and extends around the circumference of the circular wedge


105


to a stopper


114


that divides the tapered upper surface


110


from a second edge


113


of the depression


108


. When the circular wedge


105


is assembled onto the arm


102


(

FIG. 6B

) it can rotate freely about the shaft


111


of the arm


102


except when moved into engagement with the protrusion


112


. The depression


108


is sufficiently wide to receive the protrusion


112


. When the arm


102


is assembled to the coupler


96


, a spring washer


106


(

FIG. 5

) is preferably positioned on the arm beneath the circular wedge


105


.




The operation of the coupler


94


is as follows. A scaffold member (not shown) is placed within the pocket


100


. The lever


96


is swung over the scaffold member and the arm


102


is rotated into the slot


104


in the lever


96


. The circular wedge


105


rests against spring washer


106


, which rests on the lever


96


. The depression


108


rests against the protrusion


112


. To tighten the locking device, the circular wedge


105


is pressed against the lever


96


and rotated to position the protrusion


112


against a leading edge


117


of the tapered upper surface


110


. As the circular wedge


105


is further rotated (e.g. by use of a wrench), the wedge action of the surface


110


against the protrusion


112


presses the lever


96


against the scaffold member within the pocket


100


, thereby locking the scaffold member to the coupler


96


. The stopper


114


limits the rotation of the circular wedge


105


against the protrusion


112


thereby preventing the circular wedge


105


from being over-rotated. The spring washer


106


secures the circular wedge


105


against slipping once it is tightened.




A triple coupler


120


of

FIGS. 7

to


10


include a bolt-and-nut vertical support coupler


122


, as in

FIGS. 1

,


2


and two horizontal couplers


124


. As best depicted in

FIG. 8A

, each coupler


124


has a base


126


with a rear vertical plate


214


and a bottom plate


213


joined at a right angle to a bottom edge of the rear vertical plate


214


. A latch plate


209


is joined to the top edge of the rear vertical plate


214


and extends outwardly and slightly downwardly. A square hole


210


extends through the latch plate


209


. Two flanges


211


extend along opposite edges of the plates


213


,


214


. The inner edges of the flanges


211


define a arcuate pocket


144


(FIG.


7


). The flanges


211


have aligned holes


212


adjacent the outward end of the plate


213


.




An inner lever


128


is hinged to the holes


212


of the base


126


. The inner lever


128


, as shown in

FIG. 8B

, has a curved plate


215


with a slot


218


defined at its lower edge. The curved plate


215


has two upper ears


216


at its upper corners and two lower ears


241


at its lower corners. Aligned holes


217


extend through each of the ears


241


and aligned holes


240


extend through each of the ears


216


. A hinge pin


136


(

FIGS. 9

,


10


), extending through holes


212


and


217


, pivotally connects inner lever


128


to the base


126


.




A hand lever


130


shown in

FIG. 8C

is also pivotally connected to the inner lever


128


. The hand lever


130


has a main plate


219


with a curved handle


221


extending downward from its lower edge. A narrow elongate vertical hole


225


is cut through the centre of the main plate


219


. A wide upwardly open slot


224


extends downward from the upper edge of the main plate


219


. Two side plates


220


are joined at right angles to upper side edges of the main plate


219


. Two aligned holes


223


are defined in the outermost ends of the side plates


220


and two aligned holes


222


are defined in the side plates


220


at a intermediate location. The specified hinge pin,


150


(

FIGS. 9

,


10


) extend through pairs of holes


223


and


240


to pivotally connect hand lever


130


to the inner lever


128


as best seen in FIG.


9


.




A T-shaped catch assembly


164


of

FIG. 8D

is comprised of a pin member


226


and a hook member


227


. The pin member


226


has a circular protrusion


229


extending from each end. The protrusions


229


are slightly smaller in diameter than the holes


222


in the hand lever


130


. The pin member


226


also has a square hole


228


extending through it. The hook member


227


has a plate


231


with a hook


230


at one end. Extending from an opposite end of the plate


231


is a tapered neck


232


, which joins to a rectangular section


233


that is slightly smaller in size than the hole


228


in the pin member


226


. The rectangular section


233


is joined to a bolt section


234


threaded for engagement by a nut


236


.




To assemble the hook member


227


to the pin member


226


, the bolt section


234


and the rectangular section


233


of the hook member are inserted through the hole


228


in the pin member


226


. The nut


236


is then threaded onto the bolt section


234


to retain the pin member on the hook member. The T-shaped catch assembly


164


is then connected to the hand lever


130


by outwardly flexing the side plates


220


and inserting projections


229


of the pin member


226


into the holes


222


of the hand lever


130


.




A security device


134


,

FIGS. 9

,


10


, has a catch


137


slidably positioned at an outer face of the hand lever


130


. An L-shaped hook member


138


having a hook


139


and a plate


141


joined at a right angle is slidably positioned at the inner face of the hand lever


130


. The catch


137


and the plate


141


of the L-shaped hook member


138


are interconnected and held in position by a screw


143


extending through the hole


225


in the hand lever


130


. A spring


140


is located in the hole


225


between an extension


142


of the L-shaped hook member


138


protruding through the hole


225


and one end of the hole


225


. The spring


140


is retained in the hole


225


by the plate


141


and the catch


137


, which block opposite sides of the hole


225


. The catch


137


and the L-shaped hook member


138


are biased away from the handle


221


by the spring


140


.




The operation of the coupler


124


is described with regard to

FIGS. 9 and 10

. A scaffold member


160


is placed in the pocket


144


. The hand lever


130


is used to rotate the inner lever


128


to close the pocket


144


. At the same time, the T-shaped assembly


164


is rotated until the hook


230


is inserted into the hole


210


of the base


126


and hooked around the plate


209


. The hand-lever


130


is then counter rotated until the hook


139


catches around the hinge pin


136


. The spring


140


biases the hook


139


around a central part of the hinge pin


136


to secure the coupler


124


.




The over-centre design on the hand lever


130


also helps to hold the coupler


124


closed. The hook member


227


pivots around the protrusions


229


. When closed, the axis of protrusions


229


lies below a plane defined by the hinge pin


136


and the edge of the hole


210


. In this configuration, the outward force of the scaffold member


160


operating along that plane tends to further rotate the hook member


227


around the axis of the protrusions


229


to force the protrusions


229


downward rather than opening the coupler.




The functional length of the hook member


227


may be adjusted by rotation of the nut


236


to vary the force required to release the hand lever. A set of double convex washers (not shown) are placed over the bolt end


234


before threading the nut


236


onto the bolt end


234


in order to provide the resistance necessary to accommodate the over centre locking action of the hook


230


.




To release coupler


124


, the catch


137


is depressed towards the handle


221


to press the extension


142


against the spring


140


. The compression of the spring


140


allows the L-shaped hook member


138


to clear the hinge pin


136


when the hand lever


130


is rotated so that the protrusions


229


are above the plane of the hinge pins


136


and the edge of the hole


210


.




The gripping action of the hand lever coupler


124


coupler may not be as secure as other couplers described herein but has the advantage of rapid action.




It will be understood that the grip of the couplers herein described can be improved by designing some indentations on portions of the couplers which contact the scaffolding members. For example, the grip of the coupler described with reference to

FIGS. 7

to


10


can be improved by designing some indentations on the curve plate


215


which contacts the scaffold tube.




Both the coupler and the scaffold members described herein are typically comprised of steel or aluminum but may be made of any suitable material. Additionally, the scaffold members are shown to be tubular but may be of other cross-sectional shapes including rectangular members.




Alternative arrangements of the triple coupler are contemplated including interconnecting the couplers at other angles or pivotally interconnecting them. Additionally, other means of interconnecting the couplers may be used such as welding or casting as a unitary assembly.




Although the couplers may be used in different orientations, it is preferable to utilize a bolt-and-nut coupler for the vertical scaffold member because it achieves a firmer grip and is less prone to unintended loosing.




It will also be understood that the couplers described with respect to

FIGS. 3

to


9


may be used for coupling devices other than triple couplers. In particular, they may be used for an orthogonal, a parallel or a rotatable two coupler apparatus.




The above description of embodiments should not be interpreted in any limiting manner since variations and refinements can be made without departing from the spirit of the invention. The scope of the invention is defined by the appended claims and their equivalents.



Claims
  • 1. A coupling apparatus for interconnecting three scaffold members comprising:a support coupler and two connector couplers for attachment to three respective scaffold members; the support coupler having a base interconnected to the connector couplers, a lever hinged to the base, and a locking device, the base and the lever defining a pocket for laterally receiving a length of a scaffold member; the two connector couplers each defining a pocket for receiving a length of a scaffold member and having a locking device; each of the locking devices being movable from a release condition, to allow a scaffold member to be positioned in or removed from the pocket, to a locked position, to secure the scaffold member in the coupler; wherein the pockets are oriented to secure three respective scaffold members at relative angles to each other; wherein the pocket of at least one of the two connector couplers is defined by a base interconnected to the support coupler and a lever hinged to the base, the base and the lever defining the pocket for laterally receiving a length of a scaffold member; and wherein the locking device of the at least one of the two connector couplers comprises: an arm hinged to the base of the at least one of the two connector couplers; the lever having an slot adapted to receive the arm; the arm defining a hole positioned to extend beyond the lever when the arm is within the slot; a wedge adapted for insertion through the hole to slidably move against the lever when the arm extends within the slot to wedge the arm within the lever whereby the scaffold member is locked within the at least one of the two connector couplers.
  • 2. The coupling apparatus of claim 1 wherein the wedge further comprises:a wide end which is wider than the hole is long; and an hole defined in a narrow end of the wedge adapted receive a blocker to prevent the narrow end of the wedge from passing through the hole.
  • 3. The coupling apparatus of claim 1 wherein the base, of the at least one of the two connector couplers, further comprises a means of limiting the rotation of the arm from a vertical extension when the arm is not engaged with the lever.
  • 4. The coupling apparatus of claim 3 wherein the means of limiting the rotation of the arm comprises a stopper plate extending from the base, of the at least one of the two connector couplers, outside the pocket adjacent the hinge.
  • 5. A coupling apparatus for interconnecting three scaffold members comprising:a support coupler and two connector couplers for attachment to three respective scaffold members; the support coupler having a base interconnected to the connector couplers, a lever hinged to the base, and a locking device, the base and the lever defining a pocket for laterally receiving a length of a scaffold member; the two connector couplers each defining a pocket for receiving a length of a scaffold member and having a locking device; each of the locking devices being movable from a release condition, to allow a scaffold member to be positioned in or removed from the pocket, to a locked position, to secure the scaffold member in the coupler; wherein the pockets are oriented to secure three respective scaffold members at relative angles to each other; wherein the pocket of at least one of the two connector couplers is defined by a base interconnected to the support coupler and a lever hinged to the base, the base and the lever defining the pocket for laterally receiving a length of a scaffold member; and wherein the locking device of the at least one of the two connector couplers comprises: an arm hinged to the base of the at least one of the two connector couplers, the arm having a protrusion at a free end; the lever having an slot sized to receive the arm; a circular wedge pivotally mounted on the arm, the circular wedge circumferentially increasing in thickness to define a cam surface for engagement with the protrusion; the circular wedge being rotatable on the arm between the lever and the protrusion in a direction of increasing thickness to create a wedging action between the protrusion and the cam surface acting to press the lever onto the scaffold member to lock the scaffold member within the pocket.
  • 6. The coupling apparatus of claim 5 wherein the circular wedge further comprises a stopper at a widest thickness of the circular wedge adapted to prevent the circular wedge from rotating beyond the stopper.
  • 7. A coupling apparatus for interconnecting three scaffold members conspiring:a support coupler and two connector couplers for attachment to three respective scaffold members; the support coupler having a base interconnected to the connector couplers, a lever hinged to the base, and a locking device, the base and the lever defining a pocket for laterally receiving a length of a scaffold member; the two connector couplers each defining a pocket for receiving a length of a scaffold member and having a locking device; each of the locking devices being movable from a release condition, to allow a scaffold member to be positioned in or removed from the pocket, to a locked position, to secure the scaffold member in the coupler; wherein the pockets are oriented to secure three respective scaffold members at relative angles to each other; wherein the pocket of at least one of the two connector couplers is defined by a base interconnected to the support coupler and a lever hinged to the base, the base and the lever defining the pocket for laterally receiving a length of a scaffold member; and wherein the locking device of the at least one of the two connector couplers comprises: an over-centre hand-lever mechanism for intercoupling the base and the lever of the at least one of the two connector couplers, the over-centre hand-lever mechanism having an adjustable length and being selectively actuatable when intercoupling the base and the lever to lock the lever and the base to a scaffold member.
  • 8. The coupling apparatus of claim 7 wherein the over-centre hand lever mechanism includes:a hand lever that is hinged to the lever of the at least one of the two connector couplers; and an adjustable length hook member that is hinged to the hand lever; wherein the adjustable length hook member is selectively engagable with the base of the at least one of the two connector couplers and the over-centre hand lever mechanism is selectively actuatable to lock the lever and the base to a scaffold member by turning the hand lever about its hinge with the lever while the adjustable length hook member is engaged with the base.
  • 9. The coupling apparatus of claim 8 further comprising a latching device which operates, when the locking device is locked, to clamp the hand lever to the lever, the clamping device comprising:a second hook member attached to the hand lever and biased to latch the hand lever in locked position.
US Referenced Citations (17)
Number Name Date Kind
1706214 Davidson Mar 1929 A
3749429 Hauber Jul 1973 A
3999825 Cannon Dec 1976 A
4011638 Holt et al. Mar 1977 A
4355922 Sato Oct 1982 A
4426171 Layher Jan 1984 A
4443128 Yamamoto et al. Apr 1984 A
4566819 Johnston Jan 1986 A
4632221 Stanford Dec 1986 A
4639979 Polson Feb 1987 A
4660870 Donley Apr 1987 A
5167466 Hsieh Dec 1992 A
5259690 Legge Nov 1993 A
5427465 Sato Jun 1995 A
6004063 Adams, Sr. Dec 1999 A
6168345 Legge Jan 2001 B1
6283425 ILljevik Sep 2001 B1
Foreign Referenced Citations (7)
Number Date Country
878880 Jun 1953 DE
1684361 Oct 1970 DE
2753067 May 1979 DE
2234804 Jan 1975 FR
2081797 Feb 1982 GB
11172912 Jun 1999 JP
WO8806222 Aug 1988 WO